theme: {
header: {
icon: '<url>' // URL to a custom icon. To make it fit properly, use a size of 137px by 30px.
// The colors can be represented by a hex value without the # (for example: FF0000).
backgroundColor: '3a3f4e',
buttonAndBadgeBackgroundColor: 'f9b659',
buttonAndBadgeTextColor: '222222',
textColor: '000000',
}
}